C120 on a 40mm neck on a 80cm dish?

[kamaleon]

Hi folks

Trying to figure out how i could squeeze the extra few dB from my setup (there's the odd transponder on the odd bird that i can't lock to) i was wondering if it'd be possible and a good thing to do, to get a C120 lnb like the invacom quad or inverto and a separate feedhorn and mount it on my 80cm dish. Would this give me a better performance than a regular 40mm lnb from the same make? I can't really fit a dish bigger than 80 cm outside my window...

Cheers

 

[Llew]

I originally had an 40mm Invacom with a DIY 40 -22mm collar on my SMW dish. There was marginal improvement upon changing to a C120 invacom, probably because of slight inaccuracies in my homemade collar.

Don't think you'll see much in the way of extra signal.

Llew

 

[kamaleon]

Hi Llew, thanks for that feedback ;)

Hi think we might have too issues here actually:

- on the one hand I'm wondering if a C120+feedhorn would pickup more signal due to its bigger size

- on the other hand i'm supposing a C120 lnb is *better* than a non-C120 of the same model

do any of my assessments stand correct?

 

[Llew]

Same innards no doubt. Depends if you have a good feedhorn/dish match.

I dug out the feedhorn that I used to use with my SMW LNB, a match for the SMW dish.

 

[kamaleon]

Same innards no doubt. Depends if you have a good feedhorn/dish match.

Sorry mate, english's not me main language (i'm from jamaica inna africa innit ). Say that again?

regarding the good feedhorn/dish match i guess i wouldn't, as i'd be using the feedhorn on an 80cm dish designed for 40mm lnb

 

[rolfw]

I would very much doubt whether you will make any gain at all with a C120 feedhorn on a standard 80cm offset dish.

 

[kamaleon]

Hi rolfw,
why exactly would that be?

then there's the other issue - comparing a c120 invacom quad lnb, does it have the exact same components than the same invacom on a 40mm form?

 

[rolfw]

The benefit of using a C120 feedhorn, is that when used with a dish to which it is matched, it should give near perfect dish illumination, so unless you can find a feedhorn specifically designed to illuminate your 80cm dish, I can't see any real advantage over an LNBF. Don't know about the Invacom innards.

 

[Llew]

Same spec for C120 and 40mm versions -

http://www.invacom.com/documents/Single_002.pdf

No doubt similar for twin etc.

Llew

 

[kamaleon]

Alright then, cheers for these infos.

 

[satsid]

hi m8,for a C120+feedhorn,i would not bother with anything smaller than a 1.2 meter dish.
sid